But I have no idea what monitor to look for or what aspects make a good monitor?!
Basic choices:
Apple TB display:
+ Lovely high-def (2560x1440) 27" display
+ Adds extra webcam, microphone half-decent speaker system, Ethernet, Firewire, extra USB2 ports with just one cable.
+ Includes a Magsafe PSU for your laptop.
- Expensive
- Some people hate glossy, glass-fronted displays
- USB2, not USB3
- Loses some of its Unique Selling Points If you don't use Firewire or Ethernet.
- Restricted tilt/swivel & no height adjustment.
- Will (probably) only ever work with post-2011 Macs. Forget plugging in your PC, XBox, Bluray Player etc.
...may have been updated by December, but don't hold your breath.
Third-party 27" 2560x1440 displays: Lots of options from Dell and others discussed elsewhere in this forum.
+ Comparable image quality to Apple TBD
+ Substantially cheaper
+ Anti-glare versions available
+ Tilt/swivel/height/pivot adjustment usually better than TBD.
+ Lots of inputs for different equipment
- No Magsafe, no Ethernet, No Firewire, No webcam, no microphones, no speakers (mostly - some have optional soundbars).
- USB hub needs an extra cable, lots of reports of "USB3" hubs not working well.
~ Look for one with DisplayPort input and get a MiniDisplayPort to DisplayPort cable: otherwise you'll need the (expensive)
Dual Link DVI adapter (not the regular one).
Third party 24" 1920x1200 display (My recommendation: Dell U2412M)
+ Decent size, decent resolution much easier on the wallet
~ Use either Displayport cable or regular DVI adapter
+/- everything else said about third-party 27" screens
Third party ??" 1080p monitor or TV
+ Cheap, big screens. Great for gaming.
- Relatively low resolution - larger (27"+) screens of this type sound like a bargain but will look blocky when used as a desktop monitor.
~ Use HDMI adapter
Personal recommendation is the Dell 2412M (24") - but I'm pairing it with a 17" MacBook Pro on a riser stand, so I get a dual-screen setup. With an 11" Air, the internal screen isn't going to be so hot, so I'd look at 27" options.
Minor warning: some third party DisplayPort & HDMI monitors have a glitch with some Macs. Check before buying, but if you get stuck with one see the fix
here.
The best monitor for a mac is the Thunderbolt Display. The worst mouse is the Magic Mouse. You're better off with the Magic TrackPad.
Seconded about the Tragic Mouse - although some people seem to like them.
I do like the Magic Trackpad for general use, but there are still some things (graphics, games) that need a mouse.
(For benefit of original poster) pretty much any USB, Wireless+USB transmitter or Bluetooth mouse will work with a Mac. Go to a real shop and find one that feels comfortable.